Many circumstances exist in which persons are subjected to environments containing air-borne particles and/or gases that to them specifically or to people generally are obnoxious. Certain people, for example, due to their particular physiological condition suffer an adverse effect when subjected to particular naturally occurring gases, e.g. ozone, and dust, e.g. selected pollens and spores of fungi and bacteria. In other circumstances, due to the nature of the particular task and/or materials employed, workers on farms and in factories, mines, the construction industry and the like are required to often perform their occupations in environments containing obnoxious quantities of air-borne dust, other solid particles and/or liquid particles and/or gaseous fumes and vapors which are annoying or detrimental to health.
To attempt to minimize the problems posed by such air-borne materials, various helmets and masks have been proposed previously to be worn about the head or nose, with or without the mouth in the latter, to improve respiration. Such respirators previously proposed, however, have not proven to be totally satisfactory due to one or more drawbacks stemming from being too bulky and cumbersome, interferring with or distorting of the wearer's vision, not providing adequately if at all for exhaustion of the wearer's breath thereby requiring intermittent removal of the respirator with the attendant danger and opportunity for inhalation of obnoxious material, restricted for suitable use to wearers of limited facial shapes and contours, cleanable only with difficulty of screened obnoxious materials, devoid of means for coupling to and uncoupling from an air supply line with suitable speed and ease, devoid of suitable means, if any, for regulating respirator inlet air supply, and/or limited for use with air supply lines of undesirably restricted pressures.
Accordingly, a search has continued in the art for an improved respirator which overcomes and eliminates the above and other drawbacks of prior art respirators.